The invention relates to processing of textile fibers into a sliver, and particularly to apparatus and method for supplying the fibers uniformly in a nonturbulent manner for level distribution in the chute of a chute feeder of a carding machine and the like.
Conventionally, fibers, particularly cotton, are opened from a bale and cleaned on machines typically called blowroom machines which open and separate the fibers for trash removal. In the opening process, it is desirable to open the fiber masses and individualize the fibers as much as possible for cleaning and further processing. Fiber is delivered from the blowroom machines to a feeding system which feeds the carding machine. In the carding process, the fibers are straightened and aligned parallel prior to being drawn off in the form of a sliver.
A common card feeding system is a chute feed having vertical chutes in which fibers are accumulated and fed. In chute feeders, the fiber material is compressed and delivered to the carding machine in the form of a compacted fiber batt. The fiber flock is delivered to the entrance of the chute feed by a fiber-laden airflow. The fiber-laden air enters the entrance of the chute feeder and it is deposited in a reserve section of the chute above a top feed roll. The top feed roll feeds the fiber flock into an formation section of the chute where the fiber flock is compressed into the fiber batt. Bottom delivery rolls convey the fiber batt to the licker-in of the carding machine. By controlling the weight of the fiber batt, uniform sliver is produced by the carding machine.
The problem of supplying a fiber batt of a desired uniform weight is one to which considerable attention has been given in the art. For example, U.S. Pat. Nos. 4,476,611 and 4,387,486 disclose controlling the weight of a fiber batt by controlling the bottom feed roll speed and the speed of the compacting plate in response to a sensed weight output of the batt. Either directly or indirectly, the aforementioned parameters are controlled in response to the operation speed of the carding machine.
The conditions under which the fibers are delivered and deposited in the chute directly affect the performance of the chute feed in producing a fiber batt of uniform weight. In particular, the delivery of the fiber flock by airflow into the reserve section of the chute feed has typically been in a rather uncontrolled fashion resulting in non-level fiber distribution as pressure varied. Typically, a higher level of fibers is accumulated at the side of the chute feed remote from the entrance side due to the patterns flow paths of incoming transport air. Uneven distribution of fiber can occur across the entire width of the chute feed. The resulting batt of the fibers delivered at the outlet of the chute feed may have an uneven bulk density across its width. It has been found according to the present invention that a flat or level distribution of the fiber flock across the width of the reserve section results in uniform pressure imposed upon the fiber flock and thus a uniform feeding of flock by the top feed roll. The fibers are then delivered by the feed roll and accumulated evenly across the width of the chute of the formation section provides more accurate control over the uniformity of the weight and bulk density of the fiber batt delivered to the card. The end result is that the production of a more uniform sliver by the carding machine is carried out in an efficient manner.
Accordingly, an object of the present invention is to provide apparatus and method for uniformly supplying fiber flock to a chute feeder.
Still another object of the present invention is to provide an apparatus and method for providing a flat or level distribution of fiber flock in a chute of the reserve section of a chute feed so that the fiber is subjected to a uniform pressure across the chute for feeding.
Still another object of the present invention is to supply fiber flock to a chute feed in a nonturbulent manner resulting in a uniform and level distribution of the fiber across the chute of the chute feed reserve section.
Yet another object of the present invention is to provide an apparatus and method for supplying fiber flock to a chute feeder wherein the weight per unit length output of a fiber batt is more accurately controlled.